The present invention relates to thermal imaging cameras and, especially, to thermal imaging cameras having improved durability and ergonomic features.
Thermal imaging cameras (xe2x80x9cTICsxe2x80x9d)are a relatively new tool used, for example, by firefighters and other safety personnel to provide the ability to see heat sources in situations of limited visibility (for example in heavy smoke or darkness). Thermal imaging cameras find use in many scenarios including, but not limited to, executing search and rescue missions, assessing fire scenes, locating the seat of fires, determining the size and location of hot spots, identifying potential flashover situations, determining entry and ventilation points, evaluating hazardous material situations, providing an incident command xe2x80x9ceye in the skyxe2x80x9d, providing vehicle navigation, preplanning fire code inspections and assisting law enforcement officers.
Many thermal imaging cameras use ferroelectric thermal imaging. Ferroelectric cameras are solid-state infrared imagers that measure changes in heat by sensing changes in capacitance. The focal plane includes a plurality of small ceramic pixels that are made of sensing materials such as barium strontium titanate. An example of such a camera is the Argus 2 TIC sold by MSA and shown in MSA Bulletin No. 0119-23 (1999).
Pyroelectric vidicon tube cameras also detect changes in capacitance. Because the capacitance of a fixed scene on the focal plane does not change, the visible scene temperature must be artificially manipulated to generate an image in the case of pyroelectric and ferroelectric cameras. In such cameras, the blades of a chopper pass in front of the detector and effectively change the scene temperature with each pass. Each pass of a chopper blade causes a change in capacitance and allows the detector to see an infrared image. Examples of pyroelectric vidicon tube cameras are the Argus TIC and the Argus Plus TIC, previously sold by MSA and shown in MSA Bulletin Nos. 0105-16 (1997) and 0105-16 (1998), respectively.
Recently, microbolometers have been used in thermal imaging cameras. A microbolometer thermal detector is a sensor that measures changes in heat and infrared energy. It measures heat by sensing the changes in resistance of each pixel in the focal plane. The microbolometer detector is constructed of an array of pixels that are made of sensing materials such as vanadium oxide. Pixel resistance changes are directly related to temperature and allow the camera to produce an infrared image without the use of a chopper as is required with pyroelectric and ferroelectric cameras.
Because of the harsh conditions in which thermal imaging cameras are used, such cameras are preferably very durable. In the case of thermal imaging cameras used by firefighters, for example, the cameras can be exposed to extremely high temperatures as well as very wet conditions. Moreover, these cameras must also be adapted to dissipate any excess heat generated inside the camera due to its internal electronics. Although thermal imaging cameras should be durable, they should also be suitable for use by individuals having somewhat limited mobility and dexterity. In that regard, firefighters are equipped with protective clothing, including thick gloves, that limit their ability to accomplish certain tasks. Currently available thermal imaging cameras satisfy the above criteria to differing degrees. It, therefore, remains very desirable to develop thermal imaging cameras having improved ergonomics and durability.
The present invention provides a thermal imaging camera including generally a housing encompassing a thermal imaging core, a first handle, and a battery compartment. The housing is preferably positioned at a first end of the first handle and the battery compartment is positioned at the opposite end of the first handle. By positioning the first handle intermediate between the housing and the battery compartment, the center of gravity of the thermal imaging camera coincides generally with the handle when the thermal imaging camera is in use (that is, when batteries are present within the battery compartment). The camera can also include a second handle positioned between the housing and the battery compartment, the second handle is preferably oriented generally parallel to and spaced part from the first handle and facilitates the passing of the thermal imaging camera between two users.
In another aspect, the present invention provides a thermal imaging camera including resilient material placed over or around all projecting portions of the thermal imaging camera such that when the thermal imaging camera is contacted with a plane, the resilient material will first contact the plane regardless of the orientation of the thermal imaging camera relative to the plane. In other words, if the thermal imaging camera is dropped on a generally flat surface, the resilient material contacts the surface first, thereby reducing the likelihood of damage to the camera due to the shock-absorbing properties of the resilient material.
In one embodiment, the thermal imaging camera includes a housing encompassing a thermal imaging core, a handle, and a battery compartment. The housing is positioned at a first end of the handle and the battery compartment is positioned at the opposite end of the handle. The housing has resilient material surrounding a front end thereof and a rear end thereof. Likewise, a bottom portion of the battery compartment is also surrounded by resilient material. The resilient material can be in the form of elastomeric (for example, rubber) bumpers having shock-absorbing properties.
In another aspect, the present invention provides a thermal imaging camera including a housing encompassing a thermal imaging core, a first handle and a second handle. The first handle and the second handle are positioned to facilitate passing the camera between two people without setting the camera down. Any number of two-handle configurations will work including, for example, a xe2x80x9csteering wheelxe2x80x9d configuration with the camera located in the center and a plurality of spokes extending from the camera to the outer handles or ring. As described above in one preferred embodiment, the first handle and the second handle can be positioned generally parallel to and spaced apart from each other and can be positioned intermediate between the housing and the battery compartment. When the first handle and the second handle are positioned generally parallel to each other, the handles are preferably spaced at least 2.0 inches apart, more preferably at least approximately 2.25 inches apart, and most preferably at least approximately 2.5 inches apart, over the area in which the handles are to be grasped.
The present invention also provides in another aspect a thermal imaging camera including a water-resistant housing to contain the camera components. The housing has only a front opening and a rear opening and is formed without a seam therein such that the seamless housing of the present invention has only about xc2xc of the sealing surface found in other TICs. The front opening preferably has a generally flat sealing surface; likewise, the rear opening preferably has a generally flat sealing surface both of which significantly reduce the likelihood or water intrusion into the housing.
In another aspect, the present invention provides a thermal imaging camera including a durable housing to contain at least one imaging component and at least one support member to position the imaging component within the housing without attaching or connecting the imaging component to the housing. The support member preferably has an exterior formed generally in the shape of the housing and an interior formed generally in the shape of the imaging component. The support member is preferably shock absorbing and/or thermally insulating. An example of a suitable material for the support member is a foamed polymer. Preferably, a plurality of components comprising the camera engine or camera core are positioned in the housing using such support members.
The present invention also provides a thermal imaging camera including a housing to contain at least one imaging component. The imaging component is at least partially abutted by a thermally insulating and shock absorbing material positioned between the housing and the imaging component. As discussed above, the thermally insulating and shock absorbing material can be a foamed polymer.
In another aspect, the present invention provides a thermal imaging camera including a power source that has at least a first battery and a second battery. The thermal imaging camera further includes circuitry so that power is first drawn from one of the first battery and the second battery and then from the other of the first battery and the second battery. The first battery and the second battery are preferably replaceable while the thermal imaging camera is operating. For example, the first battery can be drawn down until power is switched to the second battery. The first battery can then be replaced during operation while the camera is being powered by the second battery. Later the second battery can be replaced while the camera is being powered by the other battery and so on. In this manner, the thermal imaging camera can be operated for long periods of time without shutting down the camera to replace batteries.
In still a further aspect, the present invention provides a thermal imaging camera including a generally flat surface thereon whereby the thermal imaging camera can be set in an upright position on a generally flat surface. In one embodiment, the thermal imaging camera includes a housing encompassing a thermal imaging camera core, a battery compartment, and at least a first handle positioned between the housing and the battery compartment. In this embodiment, the bottom of the battery compartment is generally flat so that the thermal imaging camera can be set in an upright position on a generally flat surface such that the camera display is easily visible and the image thereon is also in an upright position.